Cleaning device

ABSTRACT

An improved blade type cleaning device for electrophotographic copying machines, wherein, in addition to a resilient cleaning blade having an edge in contact under pressure with the surface of an image holding body, there is provided a guide plate having one of its edges confronting the edge of the cleaning blade, the edge being so adjustable as to be brought to its confronting position with respect to the edge of the cleaning blade when it is set at the cleaning position.

United States Patent [1 1 Takahashi et a1.

[ Nov. 4, 1975 CLEANING DEVICE Inventors: Toru Takahashi, Tokyo; SyujiroKadowaki, Yokohama, both of Japan Assignee: Canon Kabushiki Kaisha,Tokyo,

Japan Filed: July 17, 1974 Appl. No.: 489,086

Foreign Application Priority Data July 20, 1973 Japan 48-82031 US. Cl.355/15; l5/256.5l Int. Cl. G03G 21/00 Field of Search 355/15, 17, 30 D;

ll7/17.5; l5/256.5l; 118/637 References Cited UNITED STATES PATENTS5/1972 Gerbasi 355/15 X 3,781,107 12/1973 Ruhland 355/15 FOREIGN PATENTSOR APPLICATIONS Germany 355/15 Primary ExaminerRichard L. MosesAttorney, Agent, or Firm-Fitzpatrick, Cella, Harper & Scinto [57]ABSTRACT An improved blade type cleaning device for electrophotographiccopying machines, wherein, in addition to a resilient cleaning bladehaving an edge in contact under pressure with the surface of an imageholding body, there is provided a guide plate having one of its edgesconfronting the edge of the cleaning blade, the edge being so adjustableas to be brought to its confronting position with respect to the edge ofthe cleaning blade when it is set at the cleaning position,

9 Claims, 10 Drawing Figures U.S. Patent Nov. 4, 1975" Sheet1of4'3,917,398

US. Patent Nov. 4, 1975 Sheet 2 of4 3,917,398

US. Patent Nov. 4, 1975 Sheet 3 of4 3,917,398

FIG. 8

FIG. IO

U.S. Patent No'v.4, 1975 Sheet4 of4 3,917,398

3 4 F v I I I Q CLEANING DEVICE BACKGROUND OF THE INVENTION 1. Field ofthe Invention This invention relates to a cleaning device for use in anelectrophotographic copying machine, and, more particularly, it isconcerned with a device that is capable of sufficiently cleaning thedeveloping agent remaining on an image holding body by mean of aresilient blade.

2. Description of Prior Art As is well known, a blade is used inordinary cases, to remove the residual toner on the surface of aphotosensitive member byscraping it with the edge of the blade, which ismade of wear-resistant rubber material. Since the cleaning device usedfor this method of cleaning is simple in construction, and can be madecompact, it is highly useful as the cleaning device forelectrophotographic copying machines. Particularly, this blade cleaningdevice exhibits satisfactory cleaning effects with a photosensitivemember of a copying machine having a flat and smooth surface coated witha substance such for example, selenium, Mylar (a trademark for apolyester film produced by E. I. du pond de Nemour & Co.), and so forth.

One example of the heretofore known blade cleaning device of theabove-described type is one wherein the blade cleaning device isdisposed on one side of a photosensitive drum with the edge of the bladebeing directed downward against the rotational direction of the drum.With rotation of the drum in a predetermined direction, the developingagent remaining on the surface of the photosensitive drum is scraped offby the cleaning blade and falls into a receptacle by its own weight.However, when the cleaning device can not be so disposed because of thelayout of the copying machine, as a whole, for example agent after beingremoved from the body surface does not fall into the receptacle by itsown weight, but stays at the blade edge with conse quent lowering of thecleaning efficiency. Moreover, in the maintenance, etc. of the copyingmachine where the photosensitive drum and the cleaning device aredismantled, the developing agent which remains at the blade edgescatters around and sticks on other parts of the copying machine topossibly bring about very undesirable results. To avoid such undesirableconsequences, it is mandatory that the position of the cleaning blade belimited to the lateral side of the photosensitive drum.

SUMMARY OF THE INVENTION It is, therefore an object of the presentinvention to provide a cleaning device for electrophotographic copyingmachines, the fixing position of which is arbitrarily selectable withrespect to the photosensitive member.

It is another object of the present invention to provide a cleaningdevice which makes it possible to reduce the quantity of residualdeveloping agent at the cleaning location and minimize the scatteringthereof to other parts of the copying machine at the time of overhaul,etc.

It is still another object of the present invention to provide acleaning device which is capable of effectively recovering thedeveloping agent for re-use.

According to the present invention, there is provided a cleaning devicefor electrophotographic copying machines which comprises an imageholding body, a resilient cleaning blade having an edge in contact underpressure with the surface of the image holding body to scrape offdeveloping agent remaining thereon, and a guide plate disposed on thesurface of the image holding body having one of its edges confrontingthe edge of the cleaning blade, the edge of the guide plate being soadjustable as to be brought to its confronting position against the edgeof the cleaning blade at least at the time when cleaning action is beingcarried out by the cleaning blade.

The resilient cleaning blade and the guide plate of the cleaning deviceare each mounted in a pivotally rotatable manner, and each of them isprovided with a pressure applying means to hold it in contact with thesurface of the image holding body under the required pressure.

The cleaning device is also provided with a conveying means to conveythe developing agent as it is being removed from the surface of a imageholding body to the lateral side. The conveying means is disposed at aposition between the confronting edges of the cleaning blade and theguide plate.

The side of the edge of the cleaning blade is given a curved projectionat least at one lateral end part thereof, and the guide plate also has acorresponding curvature of the side of the edge confronting thecurvature of its cleaning blade at the corresponding lateral end.

The cleaning device is further provided with a connecting memberconnecting the cleaning blade and the guide plate, the connecting membercausing the blade edge to constantly confront against the guide plateedge, and maintains them in a movable manner only in their mutuallyopposing directions.

The connecting member for the cleaning blade and the guide plate is madeof a resilient material so that the blade edge and the guide plate edgeconnected by the connecting member may contact each other when pressureis imparted by the abovementioned pressure applying means, and uponrelease of said pressure applying means the resiliency restores theblade edge to its position in contact under pressure with said surface.

The conveying means is moveable with respect to the edges of thecleaning blade and the guide when the cleaning blade and the guide aremoved.

The foregoing objects and detailed construction and operations of thedevice according to the present invention will become moreunderstandable from the following detailed description when read inconjunction with the accompanying drawing.

BRIEF DESCRIPTION OF THE DRAWINGS FIGS. 1 and 2 are respectivelyfragmentary side elevational views of the conventional blade typecleaning device;

FIG. 3 is a fragmentary schematic side elevational view of the bladetype cleaning device according to the present invention;

FIG. 4 is a perspective view of the cleaning device according to thepresent invention disposed on the peripheral surface part of aphotosensitive drum;

FIG. 5 is a side elevational view of the main part of the blade cleaningdevice according to the present invention;

FIGS. 6 to 9, respectively, explain the actual construction of thecleaning device according to the present invention, in which FIG. 6 is across-sectional view of the inventive device when it is ready forcleaning,

FIG. 7 is a cross-sectional view of the same device in its non-cleaningstate,

FIG. 8 is a fragmentary bottom plan view of the cleaning device, and

FIG. 9 is a fragmentary perspective view of the cleaning device withportions removed to show the connection between the blade and the guideplate; and

FIG. 10 is a perspective view showing one example of the shape of thecleaning blade and the confronting guide plate.

DESCRIPTION OF THE PREFERRED EMBODIMENT Referring first to FIGS. 1 and2, which show a conventional cleaning device of the blade type, theblade cleaner is disposed on the lateral side of a photosensitive drum.When the drum 1 having a photosensitive member A on its surface rotatesin the direction of the arrow, residual developing agent D on thesurface of the photosensitive member A is scraped off by the cleaningblade 2, and the thus removed developing agent falls into a receptacle 3by its own weight and accumulates therein.

In FIG. 2, the same cleaning device is shown mounted on the top of thephotosensitive drum 1, for the convenience of the layout of the copyingmachine. In this position of the cleaning device, however, thedeveloping agent after its removal does not properly fall into thereceptacle 3 by its own weight, but stays at the blade with theconsequence that the cleaning efficiency of the cleaning device islowered. From the standpoint of maintenance of the machine, when thephotosensitive drum and the cleaning device are dismantled foroverhauling, very undesirable results are apt to occur, such as, forexample, scattering of the developing agent remaining on the bladearound the other component parts of the machine where it accumulates.

In contrast to this, the blade cleaner according to the presentinvention, when adapted to a drum type photosensitive member is as shownin FIG. 3, in which a cleaning blade 6 has an edge in contact underpressure with the surface of a photosensitive member 5, provided on thedrum 4. In contiguity to the edge of this cleaning blade 6, there isprovided a guide plate 7 with its edge opposed to that of the cleaningblade 6. By the provision of this guide plate 7, the particulatedeveloping agent, as it is being scraped off the surface of thephotosensitive drum 4, is pushed upward in the gap between theconfronting edges of the cleaning blade 6 and the guide plate 7. It goeswithout saying that this so removed developing powder is taken away fromthe guide plate by an appropriate means. In the abovedescribedconstruction, the cleaning blade 6 is made of a material havingsufficient elasticity such as, for example, urethane rubber, etc. so asto attain satisfactory contact under pressure with the drum surface. Onthe other hand, as the guide plate 7 also plays a role of presshardeningthe toner in advance of the blade cleaning, it is preferably made of amaterial having appropriate rigidity as well as friction-resistant andautistatic properties. The guide plate 7 further serves to prevent thetoner removed by the blade 6 from back-flowing,

and it is necessary that it be made of such a structure that it iscapable of maintaining a gap between the blade edge and the guide plateedge by an appropriate pressure. Experiments conducted by the presentinventors have revealed that a guide plate made of Delrin (a trademarkfor polyacetal of E. I. du Pont de Nemour & Co.), for example, servesfor this practical purpose removed, is introduced to the receptacle forthe developing agent through the duct 9 connected to the developmentdevice 10. On the other hand, the blade 6 and the guide plate 7 arefitted to the side of the body of the copying machine in a manner sothat they are pivotally rotatable on their respective shafts 12 and 13.

FIG. 5 indicates the mutual pivotal movements of the blade 6 and theguide plate 7. As mentioned above, the blade 6 is pivotally rotatable onthe axis 12, and the guide plate 7 is pivotally rotatable on the axis13. The blade 6 is in contact under pressure with the surface of thephotosensitive member by means of a spring, etc. (not shown), whereby itis warped. This state is shown in solid line in FIG. 5, wherein a gap isformed between the edges of the blade 6 and the guide plate 7. Byremoving this pressure force, or by any appropriate expedient, the edgeof the cleaning blade 6 is caused to contact or brought adjacent to theedge of the guide plate 7. In this state, the cleaning blade 6 and theguide plate 7 move upwardly, whereby the developing agent at the edgeportions also moves upwardly along with the blade, without remaining onthe surface of the photosensitive member. In the cleaning deviceconstructed according to the present invention, contamination of thephotosensitive body surface and the surrounding parts of the copyingmachine, at the time of maintenance, can be prevented.

For the realization of the foegoing functions, in practice, severalproblems still exist. That is, the first of such problems is therequirement for constantly maintaining the gap formed between the edgeof the cleaning blade and the edge of the guide plate. If this gapbecomes non-existent, the abovementioned function can no longer beacheived. To ensure such a gap between the edges of the blade and theguide plate, any fluctuation in the size of the replacement blade shouldbe taken into consideration. For this purpose, a spacer is provided atthe end parts of the blade edge and the guide plate edge, which do notparticipate in the cleaning, so that the guide plate may be pressedagainst the cleaning blade through the spacer. The mechanism, however,is not sufficient tosolve the other problems to be describedhereinbelow.

The second problem is the requirement for the guide plate to be incontact with the photosensitive drum prior to the separation of thecleaning blade from the drum, when the cleaning blade is to be relievedfrom operative state of drum surface cleaning. In the absence of thisaction, the developing agent remains on the drum surface or is spilled,whereby it may be splashed or scattered around when the photosensitivedrum is being mounted or dismantled.

The third problem is that, even after the cleaning blade separates fromthe photosensitive drum and moves upward, the guide plate should followthe movement of the cleaning blade to maintain the state of contacttherewith. Once the cleaning blade and the guide plate separate fromeach other, the developing agent, which has so far been brought upwardlyby the edges of the blade and the guide plate when they are in contactfalls and scatters on all four sides. Such a problem is difficult to besolved by only pressing the guide plate to the cleaning blade.

The fourth and last problem is that, when the cleaning blade, which hasseparated from the photosensitive drum surface and moved upward asmentioned above, is to be repositioned on the drum surface, it must besmoothly returned to its initial state.

With a view to solving these problems most favorably, the actualconstruction of the cleaning device according to the present inventionas shown in FIGS. 6 and 7 is proposed, wherein FIG. 6 is across-sectional view of the actual construction of the cleaning deviceaccording to the present invention when it is cleaning the drum surface,and FIG. 7 is the same cleaning device in its non-cleaning state,wherein the cleaning blade and the guide plate are separated from thephotosensitive drum, and moved upward.

In FIG. 6, the cleaning blade 14 is held at one end to a fitting member16 which, in turn, is fixed on a shaft 15. The other end, i.e., thecleaning edge, of the blade 14 is brought into contact under pressurewith the cylindrical photosensitive body 17, which rotates in aclock-wise direction by causing the shaft to turn in a counter-clockwisedirection, and then is locked in its turned position. The cleaning ofthe photosensitive member 17 is carried out by the sharp corner 14 ofthe blade edge 14.

The guide plate 18 is mounted in a freely swingable manner at the tipend of an arm 21 which hangs from a shaft fixed on a frame 19. On theupper surface of the blade 14, there is fitted a plate spring 22, whichis positioned by fixing its bent portion 22 at the cleaning edge of theblade 14. The extended part 22 of the plate spring 22 beyond its bentportion 22, is inserted between the guide plate 18 and an arm 24extending toward the edge 18, of the guide plate 18 from a partitionplate 23 fixed substantially upright on the top surface of the guideplate 18. This plate spring 22 acts to press the edge portion 18 of theguide plate 18 on the photosensitive drum 17 with an appropriate springforce upon setting of the cleaning blade 14, on which it is fitted, atthe required setting position. The tip end part of this plate spring 22is further provided with an elongated hole 22 into which a pin fitted onthe lower surface of the arm 24 is inserted, as will be more clearlyunderstood from FIG. 8.

The L-shaped arm 21, which hangs from the shaft 20, has mounted thereonanother plate spring 26, by the action of which it receives a moment inthe clockwise direction around the shaft 20. Accordingly, the guideplate 18 is subjected to a force which tends to separate it from theblade 14, whereby it is positioned so that the pin 25 engages the end ofthe elongated hole 22 of the plate spring 22 farthest from the cleaningblade 14. As mentioned above, the relative position between the platespring 22 and the edge part 14,, of the cleaning blade is such that theyfit together at certain definite positions irrespective of the size ofthe cleaning blade 14, on account of which the interval between the edgepart 14, of the blade and the edge part 18 of the guide plate isconstantly maintained at a predetermined value. From a practicalstandpoint, the optimum range of the gap is from 0.5 to 5 mm.

The developing agent which has been scraped off the surface of thephotosensitive drum by the edge part 14 of the cleaning blade is pushedupward by the edges of the blade and the guide plate which are inengagement, and then conveyed sidewise by the leading screw 28 to thereceptacle 11 for the developing device, as shown in FIG. 4. Thislateral transfer of the developing agent takes place at a positionbetween the partition plate 23 fixed on the upper surface of the guideplate 18 and another partition plate 27 which is fitted around the shaft15 in a freely rotatable manner and placed on the upper surface of thecleaning blade 14 by its own weight. This leading screw 18 is in contactwith the photosensitive drum 17 by means of rolls 29 provided at bothends of the screw shaft. It rests on the drum under its own weight orunder an appropriate pressure imparted thereto, and rotates inaccordance with the rotation of the drum 17.

Next, for in order the cleaning blade 14 to be separated from thephotosensitive drum l7 and to move upward as shown in FIG. 7, the shaft15 is rotated in a clockwise direction, whereupon the blade is relievedfrom its bent state, and is restored to its original flat shape. Inconnection with this restitution, the partition plate 27 placed on theblade 14 is pushed upward, which, in turn, pushes up the plate spring 26extending from the shaft 20. This movement of the plate spring 26 by thepartition plate 27 causes the arm 21 to be subjected to a moment in andanti-clockwise direction in contrast to that effected at the time ofcleaning, whereby the edge 18, of the guide plate 18 is pushed towardand brought into contact under pressure with the cleaning blade 14 sothat the edge 14 of the blade 14 can scoop up the residual developingagent from the photosensitive drum. At this time, there still remains adownward spring force, by the plate spring 22, with the consequence thatthe edge part 18 of the guide plate does not separate from the drumsurface 17. When the blade 14 leaves a drum surface 17 and furtherrotates in the clockwise direction, the plate spring 22 then raises theam 24, and the edges of both the cleaning blade and the guide plate areraised together without discrepancy therebetween. Moreover, in thiscase, the plate spring 26 is further pushed up to increase thecontacting force of the guide plate against the cleaning blade 14, andhence both edges in no way separate from each other. Also, the raisingof the cleaning blade 14 accompanies the pushing-up of the leading screw18, whereby the rollers 29 at both ends thereof separate from the drumsurface 17. In this state, mounting and dismantling of the drum 17 andthe cleaning device as a whole, can be done freely without scatteringthe developing agent, whatsoever. Incidentally, FIG. 8 is a fragmentarybottom plan view of the present device, which is maintained in theabove-described state, as seen from the side of the photosensitive drum,in and particular, at a position in the vicinity of the plate spring 22.

' Re-setting of the cleaning blade 14 on the photosensitive drum surfacecan be done in opposite procedure to that employed at the time ofreleasing. That is to say, after the edge part 14 of the cleaning bladecontacts the drum surface 17, the edge part of the guide plate 18separates from the edge part 14 of the blade 14, and hence no scatteringof the developing agent takes place at the time of resetting.

FIG. 9 is a perspective view of the afore-described cleaning deviceaccording to the present invention, from which the positionalrelationships between the cleaning blade 14, the guide plate 18, theplate springs 22 and 26, the partition plate 23 and 27, arms 21 and 24,and the leading screw 28, can be very clearly seen.

FIG. indicates one example of the edge shape of the cleaning blade andthe guide plate. As seen from this embodimental shape, it is highlyeffective to cause one side of the cleaning blade to jut out to preventthe toner, in its transfer from one end to the other of thephotosensitive drum, from remaining on the drum or falling outside thedrum. As is shown in this figure, the, provision of a certain curvaturewith this edge projection is particularly preferable to increase thecleaning efficiency. In order to correspond to this shape of cleaningblade, the edge part of the guide plate may be given a correspondingcurvature.

As described above, the cleaning device according to the presentinvention is capable of removing the developing agent from thephotosensitive drum surface without scattering it here and there, andhence the device is highly suitable for clean operation and easymaintenance. In addition, since the device is of such construction thatthe developing agent, as scraped off, is constantly discharged from thecleaning part, so that its working (or cleaning) efficiency to veryhigh. Further,

" since the discharge of the developing agent is done by the cooperativemovement of the cleaning blade and the guide plate, the setting positionof the cleaning device with respect to the photosensitive drum can bechosen freely and arbitrarily, which remarkably contributestto thedesigning and constructing of the device. Furthermore, the developingagent as removed from the photosensitive surface can be recovered forre-use, so that the cleaning device according to the present intentionhas highly practical significance.

We claim:

1. A device for cleaning an image holding body for use in anelectrophotographic copying machine, which comprises: a resilientcleaning blade having an edge in contact under pressure with the surfaceof the image holding body to scrape off developing agent remainingthereon; and a guide plate disposed on the surface of the image holdingbody, the guide plate being so adjustable as to bring one of its edgesto a confronting position against the edge of the cleaning blade at thetime when cleaning action is being carried out by the cleaning blade.

2. A cleaning device according to claim 1, wherein said resilientcleaning blade and said guide plate are each mounted in a pivotallyrotatable manner, and are also provided with pressure applying means forholding them, respectively in contact under pressure with the surface ofsaid image holding body under a required pressure.

3. A cleaning device according to claim 1, further comprising aconveying means disposed at a position between the confronting edges ofthe cleaning blade and the guide plate to convey the developing agent asit is being removed from the surface of the image holding body, to alateral side.

4. A cleaning device according to claim 1, wherein the side of the edgeof said cleaning blade has a curved projection at least at one lateralend part thereof, and the guide plate also has a corresponding curvatureof the side of the edge confronting the cleaning blade at itscorresponding lateral end.

5. A cleaning device according to claim 1, further comprising aconnecting member connecting the cleaning blade and the guide plate,said connecting member causing the blade edge to constantly confrontagainst the guide plate edge, and maintains them in a movable manneronly in their mutually opposing directions.

6. A cleaning device according to claim 5, wherein said connectingmember is made of a resilient material so that said blade edge and saidguide plate edge connected by said connecting member contact each otherwhen pressure is imparted by pressure applying means, and upon releaseof said pressure applying means said resiliency restores said blade edgeto its position in contact under pressure with said surface.

7. A cleaning device according to claim 3, wherein said conveying meansis moveable with respect to the edges of the cleaning blade and theguide when the cleaning blade and the guide are moved.

8. A device for cleaning an image holding body which is supported by arotatable drum for circulative use in an electrophotographic copyingmachine, which comprises:

a resilient cleaning blade having an edge in contact under pressure withthe surface of the image holding body near the top portion of said drumto scrape off developing agent remaining thereon; and a guide platedisposed on the surface of the image holding body, the guide plate beingso adjustable as to bring one of its edges to a confronting positionagainst the edge of the cleaning blade at the time when cleaning actionis being carried out by the cleaning blade.

9. A device for cleaning an image holding body which is supported by arotatable drum for circulative use in an electrophotographic copyingmachine, which comprises:

a resilient cleaning blade having an edge in contact under pressure withthe surface of the image holding body near the top portion of said drumto scrape off developing agent remaining thereon; a guide plate disposedon the surface of the image holding body, the guide plate being soadjustable as to bring one of its edges to a confronting positionagainst the edge of the cleaning blade at the time when cleaning actionis being carried out by the cleaning blade;

a conveying means to convey the developing agent, which has been removedfrom the surface of the image holding body, -to a lateral side; and

a collecting means for collecting the developing agent which has beenremoved.

Patent No. 3,917,398

Inventor) TORU TAKAHASEI, ET AL.

Dated November 4. .1975

Page 1 of 3 It is certified that error appears in the above-identifiedpatent and that said Letters Patent are hereby corrected as shown below:

On the I Column Column Column Column Column Column Column Column ColumnColumn Title Page, the title "CLEANING DEVICE" should read A CLEANINGDEVICE FOR AN ELECTROPHOTOGRAPHIC COPYING MACHINE--;

the title CLEANING DEVICE" should read A CLEANING DEVICE FOR ANELECTROPHOTOGRAPHIC COPYING MACHINE---;

1, line 9, "mean" should read means-;

1, line 25, "pond" should read -Pont-;

1, line 37, "for example agent" should read for example, the developingagent,-;

2, line 20, "an image" should read the image--;

2, line 28, "its cleaning blade" should read the cleaning blade-;

2, line 28, "the corresponding" should read its corresponding--;

3, line 57, "an appropriate means" should read any appropriate means-;

4, line 1, "and" should read and hence,-;

4, line 55, "of the" should read of both the-;

UNITED STATES PATENT OFFICE CERTIFICATE OF CORRECTION Patent No.3,917,398 Dated November 41 1975 Invenwfls) TORU TAKAHASHI. ET AL. Page2 of 3 It is certified that error appears in the above-identified patentand that said Letters Patent are hereby corrected as shown below:

Column 4, lines 64 and 65, "from operative state" should read from itsoperative state-w Column 5, line 26, "wherein the" should read whereinboth the--; i

Column 6, line 2o, "18" should read --2s--;

Column 6, line 26, "Next, for in order" should read Next,

in order 'for--;

Column 6, line 36, "and" should read an-;

Column 6, line 38, "whereby the edge 18," should read whereby the edge18 Column 6, line 53, "in no way" should read --cannot-;

Column 6, line 63, "in and" should read and in- Patent No. 3r917 3UNITED STATES PATENT OFFICE CERTIFICATE OF CORRECTION Dated November 4,1975 TORU TAKAHASHI, ET AL. Inventor-(s) page 3 of 3 It is certifiedthat: error appears in the above-identified patent and that saidLetters' Patent are hereby corrected as shown below:

Column 6, line 67, "in opposite procedure" should read --in exactly theopposite procedure-;

Column 7, line 33, "to" should read --is--.

Signed and Scaled this A ttest:

RUTH C. MASON Arresting Officer C. MARSHALL DANN Commissioner oj'ParenIsand Trademarks

1. A device for cleaning an image holding body for use in anelectrophotographic copying machine, which comprises: a resilientcleaning blade having an edge in contact under pressure with the surfaceof the image holding body to scrape off developing agent remainingthereon; and a guide plate disposed on the surface of the image holdingbody, the guide plate being so adjustable as to bring one oF its edgesto a confronting position against the edge of the cleaning blade at thetime when cleaning action is being carried out by the cleaning blade. 2.A cleaning device according to claim 1, wherein said resilient cleaningblade and said guide plate are each mounted in a pivotally rotatablemanner, and are also provided with pressure applying means for holdingthem, respectively in contact under pressure with the surface of saidimage holding body under a required pressure.
 3. A cleaning deviceaccording to claim 1, further comprising a conveying means disposed at aposition between the confronting edges of the cleaning blade and theguide plate to convey the developing agent as it is being removed fromthe surface of the image holding body, to a lateral side.
 4. A cleaningdevice according to claim 1, wherein the side of the edge of saidcleaning blade has a curved projection at least at one lateral end partthereof, and the guide plate also has a corresponding curvature of theside of the edge confronting the cleaning blade at its correspondinglateral end.
 5. A cleaning device according to claim 1, furthercomprising a connecting member connecting the cleaning blade and theguide plate, said connecting member causing the blade edge to constantlyconfront against the guide plate edge, and maintains them in a movablemanner only in their mutually opposing directions.
 6. A cleaning deviceaccording to claim 5, wherein said connecting member is made of aresilient material so that said blade edge and said guide plate edgeconnected by said connecting member contact each other when pressure isimparted by pressure applying means, and upon release of said pressureapplying means said resiliency restores said blade edge to its positionin contact under pressure with said surface.
 7. A cleaning deviceaccording to claim 3, wherein said conveying means is moveable withrespect to the edges of the cleaning blade and the guide when thecleaning blade and the guide are moved.
 8. A device for cleaning animage holding body which is supported by a rotatable drum forcirculative use in an electrophotographic copying machine, whichcomprises: a resilient cleaning blade having an edge in contact underpressure with the surface of the image holding body near the top portionof said drum to scrape off developing agent remaining thereon; and aguide plate disposed on the surface of the image holding body, the guideplate being so adjustable as to bring one of its edges to a confrontingposition against the edge of the cleaning blade at the time whencleaning action is being carried out by the cleaning blade.
 9. A devicefor cleaning an image holding body which is supported by a rotatabledrum for circulative use in an electrophotographic copying machine,which comprises: a resilient cleaning blade having an edge in contactunder pressure with the surface of the image holding body near the topportion of said drum to scrape off developing agent remaining thereon; aguide plate disposed on the surface of the image holding body, the guideplate being so adjustable as to bring one of its edges to a confrontingposition against the edge of the cleaning blade at the time whencleaning action is being carried out by the cleaning blade; a conveyingmeans to convey the developing agent, which has been removed from thesurface of the image holding body, to a lateral side; and a collectingmeans for collecting the developing agent which has been removed.